Great strides have been made in recent years to develop direct vent gas appliances. Rather than obtaining combustion air from the space in which the appliance is located, the combustion chamber of a direct vent appliances is sealed from the space and takes its combustion air from the outside. This increases the safety, efficiency and environmental comfort provided by the appliance. The exhaust from the appliance is, of course, also vented to the outside.
Typically, a concentric inlet-outlet configuration is used for the incoming combustion air and the outgoing exhaust gases. The exhaust gases are vented through an exhaust pipe at the centre of the configuration. An intake pipe surrounds, but is spaced away from the exhaust pipe. The combustion air is drawn in through the space between the exhaust pipe and the intake pipe.
The combustion air absorbs heat from the exhaust gases further increasing the efficiency of the appliance and reducing the temperature of the exhaust gases. The appliance is often provided with a fan to ensure that sufficient combustion air is drawn in and all of the exhaust gases are vented from the appliance. A fan-based appliance is known as a power vented appliance. Cool exhaust and power venting allow for an appliance to be vented through an exterior wall rather than the traditional manner of venting through the roof.
The ability to install appliances through the wall significantly increases the range of possible installation positions for the appliances. An appliance can now be installed in a single unit of a high-rise apartment building without other modifications to the structure. Retrofit applications are considerably easier. An appliance can be put into an existing house without having to run a chimney through the roof or up an exterior wall.
Unfortunately, transporting and installing these appliances is not yet without difficulty. In a gas baseboard heater of the type shown in U.S. Pat. No. 5,253,635 issued Oct. 19, 1993 to Overall et al the intake pipe and the exhaust pipe are fixed to the body of the appliance at the time of manufacture.
Walls have varying thickness, typically less than two feet, and the pipes need to project beyond the wall for proper venting. This means that the pipes are usually over two feet long. Although the portion of the Overall baseboard inside the space to be heated is stated to be approximately nine inches by five inches by four feet, the length of the pipes provide a transportation depth of well over two feet.
When installing the Overall unit a hole is cut in the wall and the depth of the wall is measured. For most installations, the length of the pipes will need to be cut to fit. A long length of pipe projecting from the exterior of the wall is undesirable as it is unsightly, has less strength than a small projection, and will provides a larger target for undesired bumping or buffeting. A straight cut cannot be made through both pipes as the exhaust gases would tend to re-enter the baseboard through the intake pipe. The exhaust pipe typically extends further from the wall than the intake to allow the exhaust gases to dissipate. Thus the intake pipe must be cut around the already in place exhaust pipe. As well the entire baseboard unit has to be lifted and positioned while the cutting takes place. This can be a cumbersome and inefficient process, and may even affect the size of pipe used in order to allow for a tube cutter or saw to fit around and between the pipes.
Other problems with installing appliances are maintaining access to the appliance after installation, insulating the wall, covering the cut surface of the wall aesthetically and functionally, and installing the unit entirely from the interior.
Referring again to the Overall baseboard, after the hole and pipe are cut then the baseboard heater is mounted on the wall with the pipes projecting through the wall. Screws or other mounting devices hold the baseboard heater in place. Unfortunately, the outside diameter of the pipes and the inside diameter of the hole are not likely to match exactly. If one could make the diameters of the hole and pipes the same then it would be difficult to fit the pipes through the hole. As well, opening up the interior cavity of the wall could create air flow problems within the building resulting in drafts or condensation problems. Insulation could be placed or sprayed outside the pipes into the wall cavity, however this has the dual drawback of requiring work to be performed from the outside because the baseboard heater is in the way in the interior, and fixing the unit in place, making removal difficult for repair or replacement.
After the hole is cut, there is an exposed area of the wall surrounding the pipes that needs to be protected. Again, insulation could be used, however this needs to be done from the outside and is unlikely to be aesthetically pleasing in any event. As well, the exterior surface may actually be chipped or roughened on the outside edge. This is particularly true because it is advisable to cut the hole in the wall from the interior, both to ensure proper placement and to avoid excessive damage to the interior surface when the tool is cutting the interior surface. Insulation may not be able to cover this type of damage. Repair work is time consuming and may require skills that the typical appliance installer does not have.
It is known to increase the size of the hole and insert a separate larger diameter pipe of approximately the same diameter as the hole. The pipe spans the internal cavity of the wall, sealing it off, and is held in place by a flange screwed to the interior surface of the wall. In order to protect the wall and seal the hole from the outside, another pipe is inserted from the outside into the first pipe. This second pipe is also held in place by a ranged screwed into the exterior wall. The flanges are made from metal and it is advisable to further seal the exterior flange using caulking compound. An example of this structure is described in the Installation Operation Instructions for the Siegler Model LSB 10-2D, previously published by Lear Siegler (Canada) Ltd. of Orillia Ontario, Canada. Although the Siegler product could be used to improve the installation procedure for the Overall baseboard, it is an inefficient procedure in terms of time, effort and materials, and it still does not provide an aesthetically pleasing finish or allow the heater to be installed entirely from the interior. Also, it is not possible to insulate the internal cavity as it is blocked after the first pipe is put in place.
Rinnai America Corp. of La Grange, Ga. has marketed direct vent gas wall heaters under model nos. RHFE-551A and RHFE-1001VA with vents that seal interior and exterior surfaces of the wall about the hole. The Rinnai vents are again installed partially from the interior and partially from the exterior. A plastic sleeve is cut to length and placed in the hole from the interior. The sleeve has a flange that is fixed to the interior surface of the wall using screws. An external terminal with a exhaust pipe and a flat seal is placed in the hole from the exterior. Straps are used from the interior, through the sleeve, to pull the vent toward the interior placing the seal against the exterior surface of the wall, the terminal into the sleeve, and the exhaust pipe near the interior wall. The manifold, separate from the rest of the baseboard heater is then pushed onto the exhaust pipe. Although the wall surfaces are sealed, it is not possible to insulate the internal cavity, nor is it possible to perform the entire operation from the interior.
Baker in U.S. Pat. No. 3,550,579 issued Dec. 29, 1970 entitled Flue Seal for Gas appliance and U.S. Pat. No. 3,428,040 issued Feb. 18, 1969 entitled Gas Heater describes flue seals that are installable from the interior. U.S. Pat. No. 3,428,040 uses a series of rubber rings around a telescoping pipe. When the telescoping sections are moved together, the rings are axially compressed and deform outwardly. This brings them into contact with the hole and seals the interior from the exterior. Recognizing the difficulty of choosing appropriate rings and installing them on site, Baker improved the seal as described in U.S. Pat. No. 3,550,579 by replacing the rings with a single tapered ring that forms a skin around the telescoping pipe. The skin has a wider diameter than the hole and is slightly deformed as it is inserted into the hole. This skirt quickly and efficiently forms the seal. Unfortunately, both Baker devices have minimal sealing ability and still do not protect the exterior surface of the wall or allow for insulation of the internal cavity of the wall.
It is an object of the present invention to provide improvements for the installation of appliances. The improvements are directed toward providing solution for problems in the art, including without limitation one or more of those problems described above.
The invention can have many different aspects as will be understood from the description provided below that provide different features of installation from one side of a structure, field customization and field installability.
In a first aspect the invention provides a seal that has a resiliently deformable ring. The ring has an internal circumference and an external circumference. The external circumference deforms inwardly when inserted into a hole of smaller diameter than the external circumference and the internal circumference remains constant when inserted into a hole of greater diameter than the internal circumference. The ring rebounds to its normal position when it emerges from the hole, and the ring substantially flattens when brought against a substantially flat surface.
In a second aspect the invention similarly provides a seal with a resiliently deformable ring having a normal position. The ring also has an internal circumference, an external circumference, an upper surface and a lower surface. Each surface extends about the internal circumference from the internal circumference to the external circumference. The ring has a thickness between the upper surface and the lower surface. In order to fit through a hole the ring is deformable by inwardly collapsing the second circumference. In order to seal the hole the ring is deformable by bringing the second circumference toward the first circumference until the lower surface is substantially flat without inwardly collapsing the second circumference.
The seal may have a tubular extension from the lower surface about the first circumference.
The seal of the first aspect or the one with the extension may be provided as part of a weather vent seal kit, along with a tubular sleeve of substantially the same outer contour as the internal circumference of the seal, and along with two straps.
The kit may form part of a seal assembly assembled by inserting the sleeve through the lower surface at the first circumference until it is substantially flush with the upper surface. The sleeve would be bonded to the ring.
The ring may be formed from rubber, while the sleeve may be a rigid pipe, possibly a PVC pipe.
In a third aspect a direct vent gas appliance has a field installable air intake tube and a base cabinet combination having corresponding manual insertion alignment and retention means. The appliance could further have an exhaust pipe and exhaust outlet combination having corresponding manual insertion alignment and retention means. Alternatively, the appliance of may have one or more corresponding key hole cuts and tabs for inserting one end of the tube into the base cabinet when the indentations and tabs are aligned. The keyhole cuts and tabs allow the tube to be rotated once inserted so that the cuts and tabs are no longer aligned. They prevent the tube from being removed from the base cabinet without re-aligning the cuts and tabs.
This last appliance may also have an exhaust pipe threaded on one end and a corresponding exhaust outlet in an air box connected to the base cabinet. The exhaust pipe would be threaded to the exhaust outlet.
In a fourth aspect the invention provides an appliance installation through a structure having a first surface and a second surface and a hole connecting the first and second surfaces. The installation has the above appliance and the ring of the second aspect. The appliance is installed against the first surface, and the intake tube and exhaust pipe extend from the appliance through the hole and the ring.
In a fifth aspect the invention also provides an appliance installation through a structure having a first surface and a second surface and a hole connecting the first and second surface. The installation also has the above appliance and it has one of the above seal assemblies. The seal assembly is installed through the hole with the ring substantially flattened against the second surface. The sleeve extends the depth of the hole to approximately the first surface. The straps retain the assembly in place relative to the structure. The appliance is installed against the first surface and the air intake has a O-ring on the outside of the air intake. The air intake extends from the appliance through the sleeve and beyond the ring. The O-ring seals the intake to the sleeve.
The structure may have an internal cavity about the sleeve that is insulated after installation of the sleeve.
In a sixth aspect the invention provides a kit of one of the above appliances with the pipe and tube disassembled from the remainder of the heater.